This invention relates to apparatus for carrying out quadriceps training which comprises the components set forth in the preamble of claim 1.
The tractional force of the quadriceps muscle has a stabilizing component which is constituted by the force by which the bones of the thigh and the under-leg are pressed against each other in the knee joint. In some pathological cases in which quadriceps training is desirable the joint pressure corresponding to said force causes pain to the patient in his knee joint during such training.
The apparatus according to the invention is intended to be utilized for strength training of the quadriceps muscle in orthopedic cases, joint trouble and different paralysis conditions where progressivly increased resistance training, i.e. a gradually increased load torque which counteracts the straightening out of the leg of the patient in the knee joint is desirable.
When the leg at quadriceps training is loaded by a torque which counteracts pivoting (extension) of the leg in the knee joint, the stabilizing compressive force and the joint pressure will increase. In many cases this increased joint pressure causes the patient such a pain that quadriceps training in a conventional apparatus of the kind illustrated in FIG. 1 can not be carried out. The known quadriceps training apparatus shown in FIG. 1 comprises a stool, a chair or the like which may be converted to a bench and which is generally designated 1. At the fore edge 2 of the stool there are mounted two training apparatuses which are each generally designated 3. Each apparatus comprises a weight arm 4 along which a weight 5 may be displaced. The magnitude of the weight 5 may be adjustable. By means of a locking screw 6 the weight 5 may be fixed in the desired setting position. The weight arm 4 is rotatable on a shaft 7 on which also a torque or resistance arm 8 is rotatable or pivotable. The two arms may be set in an arbitrary angular position with respect to each other and then be rigedly interconnected by means of an apertured disc 9. The disc has a circle of bores and is rigidly united with the shaft 7 and the resistance arm 8. A spring biased bolt 14 is attached to the weight arm 4 and can be brought into engagement with anyone of the apertures of the circle of bores of the apertured disc 9.
When the bolt 14 has been brought into engagement with one of the apertures of the disc 9, the two arms 4, 8 may be rotated as one unit on the shaft 7 while defining a fixed angle with each other.
A cushion or pad 11 provided with fastening or tightening means is slidable along the resistance arm 8 by means of a sleeve 10 and may be fixed to the arm 8 at the desired distance from the axis of rotation 7 by means of a locking knob 12. By the fastening means which is tightened around the under-leg of the person, near the ankle, the resistance arm is united with the leg of the person.
At the training the knee joint(s) of the person is/are, according to the adjustment and operating manual for the quadriceps training apparatus, to be positioned coaxially with the shafts 7. During the training the patient may, among other things, carry out dynamical training, i.e. extending and bending the leg in the knee joint (the left leg), suitably under progressively or gradually increased load, and statical training (the right leg), the leg being maintained extended, loaded by a suitable torque. Hereby an auxiliary support for the weight arm 4 may be utilized.
When the knee joint of the person according to the above is so positioned that it registers with the pivot axis 7 of the quadriceps training apparatus and the patient is training with the knee joint loaded by a torque which counteracts extension of the knee joint, the bones of the knee are pressed against each other with a considerable force, which often causes the patient pain in some pathological cases, as has been set out above.